Practice-clavier.



A. C. BERGMAN.

PRACTICE ULAVIER.

APPLICATION FILED JUNE 7,1910.

1,040,852. Patented 0ct.8,1912.

I W W guLummA PLANOGRAPH cu. WASHINGTON. 11C,

AMOS C. BERGMAN, OF NEW YORK, N. Y.

PRACTICE-CLAVIER.

Specification of Letters Patent.

Patented Oct. 8, 1912.

Application filed June 7, 1910. Serial No. 565,633.

To all whom it may concern:

Be it known that I, AMOS C. BERGMAN, a citizen of the United States,residing at New York, in the county of New York and State of New York,have invented new and useful Improvements in Practice-Claviers, of whichthe following is a specification.

This invention relates to practice-claviers or instruments of the classemploying means for producing clicks or toneless sounds, and it dwellsparticularly in an improvement over my patent bearing N umber (368,003,of February 12, 1901, the object of the present invention being toprovide simplified means controlled directly or positively on movementof the regulating or actuating element of the touch-bar to indicate thepressure 011 the keys.

In the drawing, forming a portion of this specification and in whichlike numerals of reference indicate similar parts in the several views:-Figure 1 is a transverse sec tion through a portion of my improvedpractice-clavier. Fig. 2 is a fragmentary perspective view showing theoperative connections between the touch-bar and the indicating dial.Fig. 3 is a plan view of the dial.

As hereinbefore described the object of the present invention relatesparticularly to an improved means for indicating the tension on the keysand in view thereof such parts that are not essential to the elementsforming the present structure have been omitted. The casing 1 isprovided with a bottom member 2, a rear member 3, and a front member f.011 the base member is mounted a balance pin 5 which is operativelyassociated with the key 6. The said base member supports adjacent itsfront and rear ends respectively sounding bars 7 and 8 which areprovided with surfaces 9 which are designed to be engaged by adjustablesound-producing pins 10. The device will be described in the singular,that is to say, but a single key will be described as it is obvious thatthe construction of one key and the mechanism therefor is common to allthe keys throughout the instrument. At the rear, the key is rabbeted toform a projecting portion 11 which is designed to be engaged with thecushioning surface 12 on the block 13. Immediately beneath this blockand suitably spaced therefrom is a block 14 having an upper cushioningsurface 15. This block is designed to engage the key on upward movementof the forward end of such key and the block 13 is designed to beengaged by the key on downward movement of its forward end. suitablewell-known guide-pins 16 which are operatively associated with the keyfor the purpose of guiding the same in its movement.

The touch-bar 17 is pivoted, as shown at.

18, to the block 19 on the rear member 3 of the casing. This touch-barsupports a pressure spring 20 whose free terminal 21 bears against theupper surface of the key 6 at the rear end thereof. It will of course beunderstood that on movement of the touchbar in forward and rearwarddirections the desired pressure of the spring can be ob tained so as tocause the key to respond to the different touches. A facing or frontstrip 22 is supported by the casing 1, and as illustrated, an actuatingor regulating rod 23 extends therethrough and it has its rear endoperatively supported in the rear member 3. The actuating or regulatingrod is formed to provide an intermediate threaded or screw portlon 24 onwhich the follower 25 is designed to travel. This follower is providedwith a depending forked portion 2e and between the arms thereof extendsthe upper end 27 of a pivot arm 28. A pivot pin 29 connects the upperend of the pivot arm 28 with the arms of the depending forked portion ofthe follower. This follower is slidably mounted in a keeper ortubular-like guide 30 on the touchbar. The rod 23 is provided at itsouter end with a manipulating knob 31 which may be controlled by theoperator to obtain the desired movements of the touch-bar.

The indicating mechanism for designating the pressure of the spring 20on. the key consists of a dial plate 32 having the graduated portion 33near its peripheral edge and suitable scale characters 34. This dialplate is disposed horizontally with respect to the facing strip 22 andit is disposed directly beneath the same, the said strip having anexposure opening 35 which is designed so that the scale-characters ofthe dial plate will be singly presented to View of the user of theinstrument. The dial plate is apertured, as shown at 36, for thereception of the stem of a screw 37 which is supported by thefacing-strip 22. The dial-plate is apertured, as at 38, for thereception of the depending stem 39 of a connecting rod 40. This rod isformed at its rear end to pro- The base member supports vide a dependingstem 41 which extends through the aperture in the ear 42 on thedepending portion of the follower. From this construction it will bereadily under stood that on movement of the follower in either directionon its supporting or regulating rod 23 movement will be imparted to theconnecting rod to impart rotary movement to the dial plate and to causethe scale-characters and graduated portions re spectively of such dialplate to be exposed and brought into registration with the opening Theopening 35 has its wall formed to provide a pointer l9. for cooperatingwith the scale-characters and degree-marks of the indicating dial. Theposition of the exposure opening 35 with respect to the manipulatingknob 31 of the regulating rod 23 is such that the hand of the operatorwill not form an obstruction to the view of the designating charactersor degree marks of the dial plate.

The casing supports a bar 43 on which is supported a cushioning spring44; having its free extremity extending downwardly to ward the bufferblock 45 of the key 6. This spring is designed to engage the buffer 45of the key 6 to prevent the key from re bounding when pressure of thehand is released therefrom. A controlling screw 46 extends through thebar 43 and its adjustability permits the operator to hold the springunder the proper or desired stress.

I claim 1. A practice clavier comprising a casing having a recessedfront strip, a touch bar,

a regulating rod having an actuating portion located at one side of therecess, connections between the touch bar and the rod and including a.follower mounted to travel on the rod, a pointer in the recess of thestrip, a dial plate movably supported by the strip and having a portiondisposed beneath the recess and graduated to co-act with the pointer,and a rod movably connected at one end to the dial and movably connectedat its opposite end to the follower.

2. The combination with a practice clavier including a casing having arecessed front bar, a touch bar, a practice key and a spring carried bythe touch bar and bearing against the practice key, of graduated dialpivoted to the recessed front bar of the casing, a regulating rodrevolubly mounted in the easing and having an actuating portionextending through the recessed front bar, a follower adapted to travelon the regulating rod and operatively connected with the touch bar tomove the same when movement is imparted to the follower, a rod having adepending front portion pivoted to the dial and a depending rear portionpivoted to the follower, and a pointer located on the front recessed barof the casing and adapted to oo-act with the said dial.

In testimony whereof I affix my signature in presence of two witnesses.

AMOS C. BERGMAN.

Witnesses M. C. PAGKER, SAMUEL HEYMAN.

Copies 01 this patent may be obtained for five cents each, by addressingthe Commissioner of Patents,

Washington, D. G.

